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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Felix Fietkau <nbd@nbd.name>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 032/220] mt76x2: disable WLAN core before probe
Date:   Fri, 22 Nov 2019 11:26:37 +0100
Message-Id: <20191122100914.699320675@linuxfoundation.org>
In-Reply-To: <20191122100912.732983531@linuxfoundation.org>
References: <20191122100912.732983531@linuxfoundation.org>
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From: Felix Fietkau <nbd@nbd.name>

[ Upstream commit 62e04f8a31fcc375c978b7f83b4229a10c3e746d ]

If the WLAN core is still active during initialization, it might cause
the MCU or DMA to hang. This can happen during soft reboot, so disable
the core + clock early to avoid this issue.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/mediatek/mt76/mt76x2_init_common.c | 4 ++++
 drivers/net/wireless/mediatek/mt76/mt76x2_pci.c         | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2_init_common.c b/drivers/net/wireless/mediatek/mt76/mt76x2_init_common.c
index 324b2a4b8b67c..54a9e1dfaf7a4 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x2_init_common.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2_init_common.c
@@ -72,6 +72,9 @@ void mt76x2_reset_wlan(struct mt76x2_dev *dev, bool enable)
 {
 	u32 val;
 
+	if (!enable)
+		goto out;
+
 	val = mt76_rr(dev, MT_WLAN_FUN_CTRL);
 
 	val &= ~MT_WLAN_FUN_CTRL_FRC_WL_ANT_SEL;
@@ -87,6 +90,7 @@ void mt76x2_reset_wlan(struct mt76x2_dev *dev, bool enable)
 	mt76_wr(dev, MT_WLAN_FUN_CTRL, val);
 	udelay(20);
 
+out:
 	mt76x2_set_wlan_state(dev, enable);
 }
 EXPORT_SYMBOL_GPL(mt76x2_reset_wlan);
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2_pci.c b/drivers/net/wireless/mediatek/mt76/mt76x2_pci.c
index e66f047ea4481..26cfda24ce085 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x2_pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2_pci.c
@@ -53,6 +53,7 @@ mt76pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		return -ENOMEM;
 
 	mt76_mmio_init(&dev->mt76, pcim_iomap_table(pdev)[0]);
+	mt76x2_reset_wlan(dev, false);
 
 	dev->mt76.rev = mt76_rr(dev, MT_ASIC_VERSION);
 	dev_info(dev->mt76.dev, "ASIC revision: %08x\n", dev->mt76.rev);
-- 
2.20.1